The present invention relates generally to coding in communications systems and, more particularly, to turbo-coding information in stages.
Turbo-coding is known in the art as another term for parallel concatenated convolutional coding. More specifically, turbo-coding involves encoding an information sequence twice, the second encoding being performed after a random interleaving of the information sequence. Decoding is performed iteratively, and the result is reliable communication.
In many communications systems, data is transmitted in L-bit packets, where L is typically on the order of between ten and several hundred. If the receiver determines that the packet has been received in error, there may be a request to retransmit the information, referred to as an automatic repeat request (ARQ). Disadvantageously, this results in the transmission of a total of 2L bits.
Accordingly, it is desirable to provide a method and apparatus for turbo-coding which does not require a full L-bit packet to be retransmitted upon occurrence of a packet error.